Semiconductor Die Connection System and Method

ABSTRACT

A system and method for connecting semiconductor dies is provided. An embodiment comprises connecting a first semiconductor die with a first width to a second semiconductor die with a larger second width and that is still connected to a semiconductor wafer. The first semiconductor die is encapsulated after it is connected, and the encapsulant and first semiconductor die are thinned to expose a through substrate via within the first semiconductor die. The second semiconductor die is singulated from the semiconductor wafer, and the combined first semiconductor die and second semiconductor die are then connected to another substrate.

This application is a continuation of U.S. patent application Ser. No.15/375,690, filed on Dec. 12, 2016, entitled “Semiconductor DieConnection System and Method,” which is a continuation of U.S. patentapplication Ser. No. 14/875,499, filed on Oct. 5, 2015, entitled“Semiconductor Die Connection System and Method,” now U.S. Pat. No.9,520,340, issued on Dec. 13, 2016, which is a continuation of U.S.patent application Ser. No. 13/947,953, filed on Jul. 22, 2013, entitled“Semiconductor Die Connection System and Method,” now U.S. Pat. No.9,153,540, issued on Oct. 6, 2015, which is a continuation of U.S.patent application Ser. No. 13/346,398, filed Jan. 9, 2012, entitled“Semiconductor Die Connection System and Method,” now U.S. Pat. No.8,518,796, issued on Aug. 27, 2013, which applications are herebyincorporated herein by reference.

BACKGROUND

Generally, semiconductor systems may be manufactured by taking certainfunctionalities and separating these functionalities onto differentsemiconductor dies. By placing the different functionalities ontoseparate semiconductor dies, those separate semiconductor dies may bedesigned, tested, and manufactured separately from each other, therebysparing the designers from the problems associated with integrating thefunctionalities onto a single semiconductor die. This type of design cansave time and money in the overall design of the semiconductor system.

As an example of such a semiconductor system that may be designed usingmultiple dies, a semiconductor system may be broken down into a logicalfunction and a memory function. The logical function may be designed andmanufactured on a first semiconductor die and the complementary memoryfunction for the logical function may be designed and manufactured on asecond semiconductor die. The first semiconductor die and the secondsemiconductor die may then be physically and electrically bondedtogether in order to provide for a complete package that includes boththe logical functionality and the memory functionality working togetherto provide a desired function.

However, because the first semiconductor die is designed andmanufactured independently of the second semiconductor die, theconsiderations that are taken into account during the design of thefirst semiconductor die (e.g., the logic die) may be greatly differentthan the considerations that are taken into account during the design ofthe second semiconductor die (e.g., the memory die). These differencesin consideration may then lead to physical and structural differencesbetween the first semiconductor die and the second semiconductor diethat may cause problems once the first semiconductor die and the secondsemiconductor die are bonded together.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a first semiconductor die and a second semiconductordie bonded to a semiconductor wafer in accordance with an embodiment;

FIG. 2 illustrates a molding chamber that may be used to encapsulate thefirst semiconductor die, the second semiconductor die, and thesemiconductor wafer in accordance with an embodiment;

FIG. 3 illustrates a thinning of the first semiconductor die, the secondsemiconductor die, and the encapsulant in accordance with an embodiment;

FIG. 4 illustrates the formation of a redistribution layer and externalconnectors on the first semiconductor die and the second semiconductordie in accordance with an embodiment;

FIG. 5 illustrates a singulation of the semiconductor wafer inaccordance with an embodiment; and

FIG. 6 illustrates a placement of the first semiconductor die onto asubstrate in accordance with an embodiment.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the variousembodiments and are not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of embodiments are discussed in detail below. Itshould be appreciated, however, that the embodiments provide manyapplicable concepts that can be embodied in a wide variety of specificcontexts. The specific embodiments discussed are merely illustrative ofspecific ways to make and use the embodiments, and do not limit thescope of the embodiments.

The embodiments will be described with respect to embodiments in aspecific context, namely a chip on memory (CoM) architecture. Theembodiments may also be applied, however, to other chip, die, and waferconnection architectures.

With reference now to FIG. 1, there is shown a first semiconductor die101 and a second semiconductor die 103 connected to a semiconductorwafer 105. In an embodiment the first semiconductor die 101 and thesecond semiconductor die 103 may be logic chips that may be utilized toprovide a logic function. However, while the first semiconductor die 101and the second semiconductor die 103 are presented in this embodiment aslogic dies, the first semiconductor die 101 and the second semiconductordie 103 are not limited to logic dies, and may have any desiredfunctionality.

The semiconductor wafer 105 may have formed within it a thirdsemiconductor die 119 and a fourth semiconductor die 121. In anembodiment in which the first semiconductor die 101 and the secondsemiconductor die 103 are logic dies, the third semiconductor die 119and the fourth semiconductor die 121 may be memory dies that may be usedin conjunction with the first semiconductor die 101 and the secondsemiconductor die 103, respectively, in a chip on memory architecture.However, similar to the first semiconductor die 101 and the secondsemiconductor die 103, the third semiconductor die 119 and the fourthsemiconductor die 121 are not limited to being memory dies, and mayprovide any suitable functionality that may be utilized in conjunctionwith the first semiconductor die 101 and the second semiconductor die103, respectively.

The first semiconductor die 101 may comprise a first substrate 102,first active devices 104, first metallization layers 106, first contactpads 107, first external connectors 108, and first through-silicon vias(TSVs) 109. The first substrate 102 may comprise bulk silicon, doped orundoped, or an active layer of a silicon-on-insulator (SOI) substrate.Generally, an SOI substrate comprises a layer of a semiconductormaterial such as silicon, germanium, silicon germanium, SOI, silicongermanium on insulator (SGOI), or combinations thereof. Other substratesthat may be used include multi-layered substrates, gradient substrates,or hybrid orientation substrates.

The first active devices 104 are represented on FIG. 1 as a singletransistor. However, as one of skill in the art will recognize, a widevariety of active and passive devices such as capacitors, resistors,inductors and the like may be used to generate the desired structuraland functional requirements of the design. The first active devices 104may be formed using any suitable methods either within or else on thesurface of the first substrate 102.

The first metallization layers 106 may be formed over the firstsubstrate 102 and the first active devices 104 and are designed toconnect the various first active devices 104 to form functionalcircuitry. The first metallization layers 106 may be formed ofalternating layers of dielectric and conductive material and may beformed through any suitable process (such as deposition, damascene, dualdamascene, etc.). In an embodiment, there may be four layers ofmetallization separated from the first substrate 102 by at least oneinterlayer dielectric layer (ILD), but the precise number of firstmetallization layers 106 is dependent upon the design of the firstsemiconductor die 101.

The first TSVs 109 may be formed by applying and developing a suitablephotoresist (not shown), and then etching the first metallization layers106 and the first substrate 102 to generate TSV openings (filled lateras discussed below). The openings for the first TSVs 109 at this stagemay be formed so as to extend into the first substrate 102 at leastfurther than the first active devices 104 formed within and on the firstsubstrate 102, and preferably to a depth at least greater than theeventual desired height of the finished first semiconductor die 101.Accordingly, while the depth is dependent upon the overall design of thefirst semiconductor die 101, the depth may be between about 1 μm andabout 700 μm below the surface on the first substrate 102, with apreferred depth of about 50 μm. The openings for the first TSVs 109 maybe formed to have a diameter of between about 1 μm and about 100 μm,such as about 6 μm.

Once the openings for the first TSVs 109 have been formed, the openingsfor the first TSVs 109 may be filled with, e.g., a barrier layer and aconductive material. The barrier layer may comprise a conductivematerial such as titanium nitride, although other materials, such astantalum nitride, titanium, a dielectric, or the like may alternativelybe utilized. The barrier layer may be formed using a CVD process, suchas PECVD. However, other alternative processes, such as sputtering ormetal organic chemical vapor deposition (MOCVD), may alternatively beused. The barrier layer may be formed so as to contour to the underlyingshape of the opening for the first TSVs 109.

The conductive material may comprise copper, although other suitablematerials such as aluminum, alloys, doped polysilicon, combinationsthereof, and the like, may alternatively be utilized. The conductivematerial may be formed by depositing a seed layer and thenelectroplating copper onto the seed layer, filling and overfilling theopenings for the first TSVs 109. Once the openings for the first TSVs109 have been filled, excess barrier layer and excess conductivematerial outside of the openings for the first TSVs 109 may be removedthrough a grinding process such as chemical mechanical polishing (CMP),although any suitable removal process may be used.

The first contact pads 107 may be formed to connect the firstmetallization layers 106 to exterior input/output connections, such asthe first external connectors 108 (discussed further below). The firstcontact pads 107 may be formed of aluminum, although other materials,such as aluminum alloy, aluminum copper, copper, combinations of these,and the like, may alternatively be used. Further, the first contact pads107 may be formed in a variety of methods depending upon the materialused. For example, if aluminum is used the first contact pads 107 may beformed by forming a layer of aluminum over the first metallizationlayers 106, and then using a suitable technique such as photolithographyand chemical etching to pattern the aluminum into the first contact pads107. Alternatively, if copper is used the first contact pads 107 may beformed by initially forming a dielectric layer, forming openings intothe dielectric layer, depositing a barrier layer and a seed layer (notshown), overfilling the openings with copper, and then using a grindingprocess such as CMP to remove excess copper outside of the openings toform the first contact pads 107. Any suitable process for forming thefirst contact pads 107 may be used and all of these processes are fullyintended to be included within the scope of the present invention.

The first external connectors 108 may be formed to provide an externalconnection between the first contact pads 107 and external devices suchas the third semiconductor die 119 (discussed further below). The firstexternal connectors 108 may be contact bumps such as microbumps orcontrolled collapse chip connection (C4) bumps and may comprise amaterial such as tin, or other suitable materials, such as silver orcopper. In an embodiment in which the first external connectors 108 aretin solder bumps, the first external connectors 108 may be formed byinitially forming a layer of tin through any suitable method such asevaporation, electroplating, printing, solder transfer, ball placement,etc, to a preferred thickness of about 100 μm. Once a layer of tin hasbeen formed on the structure, a reflow is preferably performed in orderto shape the material into the desired bump shape.

In an embodiment the first semiconductor die 101 may be considered asmall die, e.g., by having at least one dimension that is less than adimension of that the die to which it will be bonded (e.g., the thirdsemiconductor die 119). In an embodiment, the first semiconductor die101 may have a first width W₁ (illustrated in FIG. 1) of between about 1mm and about 25 mm, such as about 9 mm. The first semiconductor die 101may also have a first length (not illustrated in FIG. 1 as it extendsinto and out of the figure) of between about 1 mm and about 32 mm, suchas about 9 mm. However, as one of ordinary skill in the art willrecognize, these illustrative dimensions are not intended to be limitingupon the first semiconductor die 101, as the first semiconductor die 101may be any desired size that is smaller than the third semiconductor die119 (discussed further below).

The second semiconductor die 103 may be similar to the firstsemiconductor die 101 in that the second semiconductor die 103 may alsobe a logic die designed to perform a logical function. Additionally, thesecond semiconductor die 103 may be formed from similar structures asthe first semiconductor die 101, and may have, e.g., a second substrate110, second active devices 111, second metallization layers 113, secondcontact pads 115, second external connectors 116, and second TSVs 117.These structures may be formed from similar materials and in similarfashions as the structures in the first semiconductor die 101, althoughthese structure may alternatively be formed from separate materials andin separate methods.

The second semiconductor die 103 may also be considered a small die, by,e.g., having at least one dimension that is less than the fourthsemiconductor die 121 (discussed further below) to which the secondsemiconductor die 103 will be bonded. As one illustrative example, thesecond semiconductor die 103 may have a second width W₂ (illustrated inFIG. 1) of between about 1 mm and about 25 mm, such as about 9 mm, and asecond length (not illustrated in FIG. 1 as it extends into and out ofthe Figure) of between about 1 mm and about 32 mm, such as about 9 mm.However, similar to the first semiconductor die 101, the secondsemiconductor die 103 may be any desired size as long as it has asmaller dimension than the die to which it will be bonded (e.g., thefourth semiconductor die 121).

Additionally, as one of ordinary skill in the art will recognize, theabove description of the first semiconductor die 101 and the secondsemiconductor die 103 are merely illustrative embodiments and are notintended to limit the embodiments in any fashion. Any suitable die,functionality of the dies, or other structures such as redistributionsubstrates or interposers, may alternatively be utilized for the firstsemiconductor die 101 and the second semiconductor die 103. These andall such dies are fully intended to be included within the scope of theembodiments.

The semiconductor wafer 105 may be a wafer upon which a plurality ofsemiconductor dies has been formed. For clarity, FIG. 1 only illustratesthe third semiconductor die 119 and the fourth semiconductor die 121,although more or less semiconductor dies may be formed within thesemiconductor wafer 105. In an embodiment in which the firstsemiconductor die 101 and the second semiconductor die 103 are logicdies, the third semiconductor die 119 and the fourth semiconductor die121 may be, e.g., memory dies that are to be used in conjunction withthe first semiconductor die 101 and the second semiconductor die 103,respectively.

The third semiconductor die 119 and the fourth semiconductor die 121 mayalso have active and passive devices with metallization layers (notindividually illustrated in FIG. 1) in order to provide a desiredfunctionality such as a memory functionality. These active and passivedevices and metallization layers may be formed in a similar fashion asthe first active devices 104 and the first metallization layers 106described above, but may alternatively be formed from differentmaterials and different methods.

Additionally, the third semiconductor die 119 may have third contactpads 125 and the fourth semiconductor die 121 may have fourth contactpads 129 in order to provide external connections to the thirdsemiconductor die 119 and the fourth semiconductor die 121,respectively. The third contact pads 125 and the fourth contact pads 129may be formed of similar materials and may be formed in a similarfashion as the first contact pads 107, although they may alternativelybe formed of different materials and in different methods than the firstcontact pads 107.

Between the third semiconductor die 119 and the fourth semiconductor die121, the semiconductor wafer 105 may have a scribe line 123 in order toseparate the third semiconductor die 119 and the fourth semiconductordie 121. The scribe line 123 may be formed by not placing functionalstructures (such as active devices) into the area intended for thescribe line 123. Other structures, such as test pads or dummy metalsused for planarization, could be placed into the scribe line 123, butwould not be necessary for the functioning of the third semiconductordie 119 or the fourth semiconductor die 121 once the third semiconductordies 119 or the fourth semiconductor die 121 have been separated fromthe semiconductor wafer 105. The scribe line 123 may have a width ofbetween about 20 μm and about 180 μm, such as about 80 μm.

The third semiconductor die 119 may be considered a large die in that ithas at least one dimension that is greater than the die to which it willbe bonded (e.g., the first semiconductor die 101). In an embodiment inwhich the third semiconductor die 119 will be bonded to the firstsemiconductor die 101, the third semiconductor die 119 may have a thirdwidth W₃ (illustrated in FIG. 1) that is larger than the first width W₁,such as between about 2 mm and about 26 mm, such as about 10 mm, and mayhave a third length (not illustrated in FIG. 1 as it extends into andout of the figure) of between about 2 mm and about 33 mm, such as about10 mm. However, these dimensions are not intended to be limiting and thethird semiconductor die 119 may have any desired dimensions as long asthey are larger than the die to which the third semiconductor die 119will be bonded (e.g. the first semiconductor die 101).

The fourth semiconductor die 121 may also be considered as a large die,in that it has at least one dimension that is greater than the die towhich it will be bonded (e.g., the second semiconductor die 103). In anembodiment in which the fourth semiconductor die 121 will be bonded tothe second semiconductor die 103, the fourth semiconductor die 121 mayhave a fourth width W₄ (illustrated in FIG. 1) that is larger than thesecond width W₂, such as between about 2 mm and about 26 mm, such asabout 10 mm, and may have a fourth length (not illustrated in FIG. 1 asit extends into and out of the figure) of between about 2 mm and about33 mm, such as about 10 mm. As such, the third semiconductor die 119 mayhave a larger footprint than the first semiconductor die 101, and thefourth semiconductor die 121 may have a larger footprint than the secondsemiconductor die 103.

The first semiconductor die 101 may be placed onto the thirdsemiconductor die 119 on the semiconductor wafer 105 in a chip on wafer(CoW) configuration. In an embodiment the first semiconductor die 101may be placed onto the third semiconductor die 119 in a face to face(F2F) configuration, with the first contact pads 107 facing and alignedwith the third contact pads 125. Once aligned, the first externalconnectors 108 and the third contact pads 125 may then be bondedtogether by contacting the first external connectors 108 to the thirdcontact pads 125 and performing a reflow to reflow the material of thefirst external connectors 108 and bond to the third contact pads 125.Any suitable method of bonding, however, such as copper-copper bonding,may alternatively be utilized to bond the first semiconductor die 101 tothe third semiconductor die 119.

An underfill material 127 may be injected or otherwise formed in thespace between the first semiconductor die 101 and the thirdsemiconductor die 119. The underfill material 127 may, for example,comprise a liquid epoxy that is dispensed between the firstsemiconductor die 101 and the third semiconductor die 119, and thencured to harden. This underfill material 127 may be used to preventcracks from being formed in the first external connectors 108, whereincracks are typically caused by thermal stresses.

Alternatively, either a deformable gel or silicon rubber could be formedbetween the first semiconductor die 101 and the third semiconductor die119 in order to help prevent cracks from occurring within the firstexternal connectors 108. This gel or silicon rubber may be formed byinjecting or otherwise placing the gel or rubber between the firstsemiconductor die 101 and the third semiconductor die 119. Thedeformable gel or silicon rubber may also provide stress relief duringsubsequent processing.

The second semiconductor die 103 may be bonded to the fourthsemiconductor die 121 on the semiconductor wafer 105 in a similarfashion as the first semiconductor die 101 is bonded to the thirdsemiconductor die 119. For example, the second external connectors 116may be aligned with the fourth contact pads 129 and then reflowed tobond the second external connectors 116 to the fourth contact pads 129,upon which an underfill material 127 may be placed between the secondsemiconductor die 103 and the fourth semiconductor die 121. However, anyother suitable manner of bonding or connecting the second semiconductordie 103 to the fourth semiconductor die 121 on the semiconductor wafer105 may alternatively be utilized.

FIG. 2 illustrates an encapsulation of the first semiconductor die 101and the second semiconductor die 103 after they have been bonded to thesemiconductor wafer 105. The encapsulation may be performed in a moldingdevice 200, which may comprise a top molding portion 205 and a bottommolding portion 207 separable from the top molding portion 205. When thetop molding portion 205 is lowered to be adjacent to the bottom moldingportion 207, a molding cavity 203 may be formed for the bonded firstsemiconductor die 101, second semiconductor die 103, and semiconductorwafer 105. Accordingly, while the shape of the molding cavity 203 willbe influenced by the size and shape of the bonded first semiconductordie 101, second semiconductor die 103, and semiconductor wafer 105, asan example only, the molding cavity 203 may have a fifth width W₅ and afirst height H₁ sufficient to house the bonded first semiconductor die101, second semiconductor die 103, and semiconductor wafer 105 and toform the dimensions of an encapsulant 211. For example, the moldingcavity 203 may have the fifth width W₅ be between about 2 mm and about450 mm, such as about 300 mm, and may also have a first height H₁ (overthe semiconductor wafer 105) of between about 20 μm and about 900 μm,such as about 700 μm.

The bottom molding portion 207 may have a set of vacuum holes 215. Theset of vacuum holes 215 may be connected to a first vacuum pump 219 inorder to reduce the pressure and generate at least a partial vacuumwithin the set of vacuum holes 215. When the bonded first semiconductordie 101, second semiconductor die 103, and semiconductor wafer 105 areplaced adjacent to the set of vacuum holes 215, this at least partialvacuum will lower the pressure in order to fix and hold the bonded firstsemiconductor die 101, second semiconductor die 103, and semiconductorwafer 105, thereby assuring that, once the bonded first semiconductordie 101, second semiconductor die 103, and semiconductor wafer 105 iscorrectly positioned within the molding cavity 203, the bonded firstsemiconductor die 101, second semiconductor die 103, and semiconductorwafer 105 will not move during subsequent processing, such as theencapsulation process.

The sidewalls of the bottom molding portion 207 may be coated with arelease material 227. This release material 227 is intended to provide anon-adhering surface for the encapsulating material, so that, once thebonded first semiconductor die 101, second semiconductor die 103, andsemiconductor wafer 105 are encapsulated, the bonded first semiconductordie 101, second semiconductor die 103, and semiconductor wafer 105 canbe easily removed from the bottom molding portion 207 without adheringto the sidewalls of the bottom molding portion 207. The release material227 may be, for example, gold, Teflon, Cr—N, combinations of these, orthe like, although any suitable release material 227 may alternativelybe utilized.

Also illustrated in FIG. 2 is a release film 229 positioned to belocated between the top molding portion 205 and the bonded firstsemiconductor die 101, second semiconductor die 103, and semiconductorwafer 105. The release film 229 may be a material that allows theencapsulant to not stick, or be released from, the surface of the topmolding portion 205 once the bonded first semiconductor die 101, secondsemiconductor die 103, and semiconductor wafer 105 has gone through theencapsulating process. The release film 229 may comprise polyimide,vinyl chloride, PC, ETFE, PTFE, PET, FEP, polyvinylidene chloride,fluorine-containing glass cloth, synthetic paper, metallic foil,combinations of these, and the like. The release film 229 may have athickness between about 20 μm and about 50 μm, such as about 25 μm.

During the encapsulation process the top molding portion 205 may beplaced adjacent to the bottom molding portion 207, thereby enclosing thebonded first semiconductor die 101, second semiconductor die 103, andsemiconductor wafer 105 within the molding cavity 203 (along with therelease film 229). Once enclosed, the top molding portion 205 and thebottom molding portion 207 (along with the release film 229 sandwichedbetween them) may form an airtight seal in order to control the influxand outflux of gasses from the molding cavity 203. The top moldingportion 205 and the bottom molding portion 207 may be pressed togetherusing, e.g., a compression tool and a force of between about 5 KN andabout 200 KN, such as between about 50 and 100 KN.

Also illustrated in FIG. 2 is the placement of an encapsulant 211 withinthe molding cavity 203. The encapsulant 211 may be a molding compoundresin such as polyimide, PPS, PEEK, PES, a heat resistant crystal resin,combinations of these, or the like. The encapsulant 211 may be placedwithin the molding cavity 305 prior to the alignment of the top moldingportion 205 and the bottom molding portion 207, or else may be injectedinto the molding cavity 203 through an injection port (not shown).

Once the encapsulant 211 has been placed into the molding cavity 203such that the encapsulant 211 encapsulates the bonded firstsemiconductor die 101, second semiconductor die 103, and semiconductorwafer 105, the encapsulant 211 may be cured in order to harden theencapsulant 211 for optimum protection. While the exact curing processis dependent at least in part on the particular material chosen for theencapsulant 211, in an embodiment in which molding compound is chosen asthe encapsulant 211, the curing could occur through a process such asheating the encapsulant 211 to between about 100° C. and about 130° C.,such as about 125° C. for about 60 sec to about 3000 sec, such as about600 sec. Additionally, initiators and/or catalysts may be includedwithin the encapsulant 211 to better control the curing process.

However, as one having ordinary skill in the art will recognize, thecuring process described above is merely an exemplary process and is notmeant to limit the current embodiments. Other curing processes, such asirradiation or even allowing the encapsulant 211 to harden at ambienttemperature, may alternatively be used. Any suitable curing process maybe used, and all such processes are fully intended to be included withinthe scope of the embodiments discussed herein.

By encapsulating the first semiconductor die 101 and the secondsemiconductor die 103 with the semiconductor wafer 105, the encapsulant211 may be utilized as an additional support structure in order tosupport and protect the first semiconductor die 101 and the secondsemiconductor die 103. This protection helps to counter the forces andstresses caused by the mismatch in sizes between, e.g., the firstsemiconductor die 101 and the third semiconductor die 119 after thethird semiconductor die 119 has been singulated from the semiconductorwafer 105.

FIG. 3 illustrates the removal of the bonded first semiconductor die101, second semiconductor die 103, and semiconductor wafer 105 (nowencapsulated with the encapsulant 211), and a thinning of theencapsulant 211 along with a thinning of the back side of the firstsemiconductor die 101 and the second semiconductor die 103 in order toexpose the first TSVs 109 and the second TSVs 117 for furtherprocessing. The thinning may be performed, e.g., using a CMP processwhereby chemical etchants and abrasives are utilized to react and grindaway the encapsulant 211, the first semiconductor die 101 and the secondsemiconductor die 103 until the first TSVs 109 and the second TSVs 117have been exposed. As such, the first semiconductor die 101 may have aplanar surface that is also planar with the encapsulant 211 and thesecond semiconductor die 103 may also have a planar surface that is alsoplanar with the encapsulant 211.

However, while the CMP process described above is presented as oneillustrative embodiment, it is not intended to be limiting to theembodiments. Any other suitable removal process may alternatively beused to thin the encapsulant 211, the first semiconductor die 101, andthe second semiconductor die 103. For example, a series of chemicaletches may alternatively be utilized. This process and any othersuitable process may alternatively be utilized to thin the encapsulant211, the first semiconductor die 101, and the second semiconductor die103, and to expose the first TSVs 109 and the second TSVs 117, and allsuch processes are fully intended to be included within the scope of theembodiments.

FIG. 4 illustrates the formation of third external connectors 401 inconnection with the exposed first TSVs 109 and the exposed second TSVs117. Optionally, prior to the formation of the third external connectors401, a redistribution layer (RDL) 403 may be formed in contact with theexposed first TSVs 109 and the exposed second TSVs 117. The RDL 403 maybe utilized to allow the third external connectors 401 that areelectrically connected to the first TSVs 109 and the second TSVs 117 tobe placed in any desired location on the first semiconductor die 101 andthe second semiconductor die 103, instead of limiting the location ofthe third external connectors 401 to the region directly over the firstTSVs 109 and the second TSVs 117. In an embodiment the RDL 403 may beformed by initially forming a seed layer (not shown) of a titaniumcopper alloy through a suitable formation process such as CVD orsputtering. A photoresist (not shown) may then be formed to cover theseed layer, and the photoresist may then be patterned to expose thoseportions of the seed layer that are located where the RDL 403 is desiredto be located.

Once the photoresist has been formed and patterned, a conductivematerial, such as copper, may be formed on the seed layer through adeposition process such as plating. The conductive material may beformed to have a thickness of between about 1 μm and about 10 μm, suchas about 5 μm, and a width along the first substrate 102 of betweenabout 5 μm and about 300 μm, such as about 15 μm. However, while thematerial and methods discussed are suitable to form the conductivematerial, these materials are merely exemplary. Any other suitablematerials, such as AlCu or Au, and any other suitable processes offormation, such as CVD or PVD, may alternatively be used to form the RDL403.

Once the conductive material has been formed, the photoresist may beremoved through a suitable removal process such as ashing. Additionally,after the removal of the photoresist, those portions of the seed layerthat were covered by the photoresist may be removed through, forexample, a suitable etch process using the conductive material as amask.

The third external connectors 401 may be formed on the RDL 403 and maycomprise a material such as tin, or other suitable materials, such assilver or copper. In an embodiment in which the third externalconnectors 401 are tin solder bumps, the third external connectors 401may be formed by initially forming a layer of tin through any suitablemethod such as evaporation, electroplating, printing, solder transfer,ball placement, etc, to a preferred thickness of about 100 μm. Once alayer of tin has been formed on the structure, a reflow is preferablyperformed in order to shape the material into the desired bump shape.

FIG. 5 illustrates the singulation of the third semiconductor die 119(bonded and encapsulated to the first semiconductor die 101) and thefourth semiconductor die 121 (bonded and encapsulated to the secondsemiconductor die 103) from the semiconductor wafer 105. In anembodiment the singulation may be performed by using a saw blade (notshown) to slice the semiconductor wafer 105 within the scribe line 123(not illustrated in FIG. 5 but illustrated in FIG. 4) between the thirdsemiconductor die 119 and the fourth semiconductor die 121, therebyseparating the third semiconductor die 119 and the fourth semiconductordie 121 from the semiconductor wafer 105. Additionally, the saw bladealso cuts through the encapsulant 211 located over the the scribe line123, causing the encapsulant 211 over the first semiconductor die 101and the third semiconductor die 119 to be aligned with each other alongthe cut.

However, as one of ordinary skill in the art will recognize, utilizing asaw blade to singulate the third semiconductor die 119 and the fourthsemiconductor die 121 from the semiconductor wafer 105 is merely oneillustrative embodiment and is not intended to be limiting. Alternativemethods for singulating the third semiconductor die 119 and the fourthsemiconductor die 121, such as utilizing one or more etches to separatethe third semiconductor die 119 and the fourth semiconductor die 121from the semiconductor wafer 105, may alternatively be utilized. Thesemethods and any other suitable methods may alternatively be utilized tosingulate the third semiconductor die 119 and the fourth semiconductordie 121 from the semiconductor wafer 105.

FIG. 6 illustrates the placement of the first semiconductor die 101(with the third semiconductor die 119 bonded to it) onto a thirdsubstrate 601. The third substrate 601 may be utilized to support andprotect the first semiconductor die 101 and the third semiconductor die119 while also being used to provide a connection between the thirdexternal connectors 401 on the first semiconductor die 101 to externaldevices (not shown). In an embodiment the third substrate 601 may be aprinted circuit board and may be laminate substrate formed as a stack ofmultiple thin layers (or laminates) of a polymer material such asbismaleimide triazine (BT), FR-4, or the like. However, any othersuitable substrate, such as an organic substrate, a ceramic substrate,or the like, may alternatively be utilized, and all such substrates thatprovide support and connectivity to the first semiconductor die 101 andthe third semiconductor die 119 are fully intended to be included withinthe scope of the embodiments.

By encapsulating the first semiconductor die 101 and the secondsemiconductor die 103 as described in the above embodiments, the firstsemiconductor die 101 and the second semiconductor die 103 are providedgreater protection from the stresses and pressures caused by theirsmaller size in relation to the third semiconductor die 119 and thefourth semiconductor die 121, respectively. By providing greater supportto the first semiconductor die 101 and the second semiconductor die 103,fewer defects may be caused by the stresses and pressures caused bytheir size mismatch, and the overall structure will be able to betterwithstand the stresses and pressures of further processing andoperation.

In accordance with an embodiment, a method for manufacturing asemiconductor device comprising connecting a first semiconductor diewith a first width to a second semiconductor die with a second width,wherein the first width is less than the second width and wherein thesecond semiconductor die is part of a semiconductor wafer, is provided.The first semiconductor die is encapsulated with an encapsulant, whereinthe encapsulant is in contact with the first semiconductor die and thesecond semiconductor die. The first semiconductor die is thinned toexpose a first through substrate via, the thinning the firstsemiconductor die removing a portion of the encapsulant, and the secondsemiconductor die is singulated from the semiconductor wafer.

In accordance with another embodiment, a method for manufacturing asemiconductor device comprising bonding a first semiconductor die to asecond semiconductor die, the second semiconductor die being part of asemiconductor wafer, wherein the first semiconductor die is smaller thanthe second semiconductor die and wherein the first semiconductor die hasfirst conductive material extending at least partially through the firstsemiconductor die, is provided. An encapsulant is placed over the firstsemiconductor die and the second semiconductor die. A portion of theencapsulant and the first semiconductor die are removed to expose thefirst conductive material, and the second semiconductor die is removedfrom the semiconductor wafer.

In accordance with yet another embodiment, a semiconductor devicecomprising a first semiconductor die with a first width and a first topsurface and at least one through substrate via extending through thefirst semiconductor die is provided. A second semiconductor die isconnected to the first semiconductor die, the second semiconductor diehaving a second width greater than the first width, the secondsemiconductor die having a first sidewall. An encapsulant encapsulatesthe first semiconductor die, the encapsulant having a second sidewallaligned with the first sidewall and having a top surface aligned withthe first top surface of the first semiconductor die.

In accordance with yet another embodiment, a semiconductor devicecomprising a first die with a first width over a second die with asecond width, wherein the second width is larger than the first width isprovided. Through substrate vias extend through the first die, and anencapsulant has a first edge planar with a top surface of the first dieand a second edge in physical contact with and planar with a sidesurface of the second die.

In accordance with yet another embodiment, a semiconductor devicecomprising a first die encapsulated with an encapsulant, wherein theencapsulant is planar with a top surface of the first die is provided.Through substrate vias extend through the first die from a bottomsurface of the first die to the top surface of the first die, and asecond die is electrically connected to the first die, the second dieextending beyond the first die in a first direction that is parallelwith the top surface, the second die having a first side that isperpendicular to the first direction and is planar with the encapsulant.

In accordance with yet another embodiment, a semiconductor devicecomprising a first semiconductor device with a first width and a secondsemiconductor device with a second width over the first semiconductordevice, the second width being less than the first width is provided. Anencapsulant extends between a first sidewall of the second semiconductordevice and a top surface of the first semiconductor device, the firstsidewall being perpendicular with the top surface, wherein theencapsulant does not extend beyond the first semiconductor device in afirst direction and does not extend beyond the second semiconductordevice in a second direction perpendicular to the first direction.

Although the embodiments and their advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the embodiments as defined by the appended claims. For example,the precise materials or methods of formation for many of the featuresmay be altered. Additionally, the precise methods used to bond thesemiconductor dies may also be modified.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the embodiments, processes, machines,manufacture, compositions of matter, means, methods, or steps, presentlyexisting or later to be developed, that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein may be utilized according to theembodiments. Accordingly, the appended claims are intended to includewithin their scope such processes, machines, manufacture, compositionsof matter, means, methods, or steps.

What is claimed is:
 1. A method of manufacturing a semiconductor device,the method comprising: bonding a first semiconductor device and a secondsemiconductor device to a first wafer; placing an encapsulant betweenthe first semiconductor device and the second semiconductor device;polishing the encapsulant, the first semiconductor device, and thesecond semiconductor device until through substrate vias have beenexposed; and sawing through the encapsulant and the first wafer.
 2. Themethod of claim 1, wherein the first semiconductor device has a width ofbetween about 1 mm and about 25 mm.
 3. The method of claim 2, whereinthe first semiconductor device has a length of between about 1 mm andabout 32 mm.
 4. The method of claim 3, wherein the sawing through theencapsulant and the first wafer forms a third semiconductor devicebonded to the first semiconductor device, the third semiconductor devicehaving a width of between about 2 mm and about 26 mm.
 5. The method ofclaim 1, further comprising forming a redistribution layer in electricalconnection with the through substrate vias.
 6. The method of claim 1,wherein the bonding the first semiconductor device to the first wafer isperformed in a face-to-face configuration.
 7. A method of manufacturinga semiconductor device, the method comprising: bonding a firstsemiconductor device to a first wafer; bonding a second semiconductordevice to the first wafer, the second semiconductor device beingseparated from the first semiconductor device by a first distance;encapsulating the first semiconductor device and the secondsemiconductor device with an encapsulant; exposing a through substratevia within the first semiconductor device using a planarization process,the planarization process also removing a first portion of theencapsulant; and forming an opening through both the encapsulant and thefirst wafer, the opening being located between the first semiconductordevice and the second semiconductor device and the opening having afirst width less than the first distance.
 8. The method of claim 7,wherein the forming the opening is performed by sawing through theencapsulant and the first wafer.
 9. The method of claim 7, wherein theforming the opening is performed by etching through the encapsulant andthe first wafer.
 10. The method of claim 7, further comprising forming aredistribution structure over the through substrate via.
 11. The methodof claim 7, further comprising bonding the first semiconductor device toa first substrate after the forming the opening.
 12. The method of claim11, wherein the first substrate is a printed circuit board.
 13. Themethod of claim 7, further comprising placing a deformable gel betweenthe first semiconductor device and the first wafer.
 14. The method ofclaim 7, further comprising placing a silicon rubber between the firstsemiconductor device and the first wafer.
 15. A semiconductor devicecomprising: a printed circuit board with a first width; a firstsemiconductor device with a second width; a second semiconductor devicelocated between the printed circuit board and the first semiconductordevice, the second semiconductor device having a third width less thanboth the first width and the second width; and an encapsulant extendingaway from the second semiconductor device to be planar with a sidewallof the first semiconductor device.
 16. The semiconductor device of claim15, further comprising through substrate vias extending through thesecond semiconductor device.
 17. The semiconductor device of claim 16,further comprising a redistribution layer connecting the throughsubstrate vias to the printed circuit board.
 18. The semiconductordevice of claim 15, wherein the third width is between about 1 mm andabout 25 mm.
 19. The semiconductor device of claim 18, wherein thesecond semiconductor device has a first length of between about 1 mm andabout 32 mm.
 20. The semiconductor device of claim 15, wherein the firstsemiconductor device and the second semiconductor device are bonded in achip on memory architecture.